CVE-2026-3298

The method "sock_recvfrom_into()" of "asyncio.ProacterEventLoop" (Windows only) was missing a boundary check for the data buffer when using nbytes parameter. This allowed for an out-of-bounds buffer write if data was larger than the buffer size. Non-Windows platforms are not affected.

CVSS 4.0

8.8CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N

EPSS

0.4% chance of exploitation in the next 30 days; higher than 33% of CVEs (scores of 2026-10-26)

CWE

CWE-787

Published

2026-04-21

Modified

2026-10-26

Record from

the NVD, synced 2026-10-26

References

• https://github.com/python/cpython/commit/1274766d3c29007ab77245a72abbf8dce2a9db4d
• https://github.com/python/cpython/commit/27522b7d6e6588f03e61099dd858cd5a9314e2f2
• https://github.com/python/cpython/commit/6c8b85b3f1d83d5697ec19880960e1eacee56688
• https://github.com/python/cpython/commit/95633d2aad4721e25e4dfd9f43dfb6e1edcbd741
• https://github.com/python/cpython/commit/f5ca38739241fe7a40a4b116d5a8a1364dd6fea7

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